Avocado extract may be able to prevent Listeria in food

A study published in the Journal of Food Science shows that extracts and isolated compounds from avocado seeds may protect ready-to-eat foods against Listeria. The main objective of the study was to chemically characterize and determine the antilisterial properties of an enriched acetogenin extract (EAE) from avocado seed, and its major acetogenin components, and compare it to two food-grade commercial antimicrobials—an avocado seed oil enriched in acetogenins (Avosafe) and a synthetic lipophilic product (Mirenat), commonly used to control Listeria. In addition, the researchers wanted to determine the acetogenin composition in pulp and seeds of the commercially relevant Hass avocado cultivar.

The researchers found that enriched acetogenin extracts from avocado seeds obtained at a laboratory scale (EAE) and commercially available (Avosafe) possess similar antilisterial properties and chemical profiles. The minimum inhibitory concentration (MIC) values of extracts and two isolated acetogenins varied between 7.8 and 15.6 mg/L, were effective at 37°C and 4°C, and showed a bactericidal effect probably caused by increased membrane permeability and lytic effects. Activity was comparable to Mirenat. The most potent acetogenins were Persenone C and A, and AcO-avocadenyne, the latter exclusively present in seed. The avocado seeds contained 1.6 times higher levels of acetogenins than pulp and total content in pulp was 199–398 times higher than MIC values.

The researchers concluded that the “avocado acetogenins possess antilisterial activity comparable to that of synthetic commercial antimicrobials, indicating that enriched extracts or isolated compounds from avocado fruit can potentially be incorporated into ready-to-eat foods as natural additives to control Listeria monocytogenes.” As a waste product of the industry, avocado seeds represent a good source of these molecules. Humans already consume acetogenins from avocado pulp above antilisterial levels; however, bioavailability and safety of the enriched extracts and isolated compounds needs further assessment.